Spellcasting expansion

internal/topdata/wiki_tables.go

@@ -452,6 +452,7 @@ func (ctx *wikiContext) classProgressionRows(levels string, projections map[stri
 		row["HasSpellProgression"] = hasSpellProgression(classRow)
 		row["HasSpellsPerDay"] = hasPerDay
 		row["HasSpellsKnown"] = hasKnown
+		row["SpellcastingAdvancementNote"] = classSpellcastingAdvancementNote(classRow, level)
 		populateClassSpellProgressionFields(row, "SpellsPerDay", spellsPerDayByLevel[level])
 		populateClassSpellProgressionFields(row, "SpellsKnown", spellsKnownByLevel[level])
 		out = append(out, row)
@@ -459,6 +460,35 @@ func (ctx *wikiContext) classProgressionRows(levels string, projections map[stri
 	return out, nil
 }
 
+func classSpellcastingAdvancementNote(classRow map[string]any, level int) string {
+	if level < 1 || isClassSpellcaster(classRow) {
+		return ""
+	}
+	notes := []string{}
+	if advancesSpellcastingAtLevel(classRow, "ArcSpellLvlMod", level) {
+		notes = append(notes, "+1 level of existing arcane spellcasting class")
+	}
+	if advancesSpellcastingAtLevel(classRow, "DivSpellLvlMod", level) {
+		notes = append(notes, "+1 level of existing divine spellcasting class")
+	}
+	return strings.Join(notes, "; ")
+}
+
+func advancesSpellcastingAtLevel(classRow map[string]any, field string, level int) bool {
+	mod, err := asInt(fieldValue(classRow, field))
+	if err != nil || mod <= 0 {
+		return false
+	}
+	return roundedSpellcastingLevelAdvancement(level, mod) > roundedSpellcastingLevelAdvancement(level-1, mod)
+}
+
+func roundedSpellcastingLevelAdvancement(level, mod int) int {
+	if level <= 0 || mod <= 0 {
+		return 0
+	}
+	return (level*2 + mod) / (mod * 2)
+}
+
 func (ctx *wikiContext) classProgressionNote(classRow map[string]any, level int) string {
 	meta, err := parseExistingMetadata(classRow)
 	if err != nil || meta == nil {